One type of image forming apparatus of the related art forms an image using a decolorable material. A color state of the decolorable material depends on a temperature of the decolorable material. For example, the decolorable material may be in a chromatic state similarly to a non-decolorable material when the image formed therewith is in use, and may turn into an achromatic state when the decolorable material is heated to a certain temperature or above.
Applying such a decolorable material to a variety of image forming operations is desirable.